Phosphorylase is an enzyme which catalyzes phosphorolysis of the substrate saccharide in the presence of inorganic phosphoric acid. The phosphorylases are generally named based on the substrate sugar molecule, and include, for example, maltodextrin phosphorylase, sucrose phosphorylase, maltose phosphorylase, cellobiose phosphorylase, trehalose phosphorylase. Such phosphorylases are useful as a reagent for the quantitative assay of the substrate of inorganic phosphoric acid or saccharide, and also useful as an enzyme applicable to the synthesis of various glycosides from phosphorylated saccharide using its catalytic property of reversible phosphorolysis.
Phosphorylases are known to be stored as intracellular enzymes in various microorganisms such as those belonging to genus Leuconostoc. 
To utilize the phosphorylase for the purpose described above, it is desirable that the purity of the enzyme preparation is increased to some reasonable level. For the purpose of obtaining such enzyme preparation, a phosphorylase producing microorganism is cultured, and after that, several complicated processes such as recovery of the cultured microorganism (cell), washing the cell, lysing the cell, isolation of enzyme fraction, and purification of the enzyme have to be carried out (for example, refer to patent documents 1 to 5). In this process, addition of a lytic enzyme or a chelating agent which is required for cell lysis becomes necessary, and further, almost all the cell components are released; therefore a heavy burden is added onto the enzyme purification process.
As the means to reduce such a load of purification, a method of increasing intracellular phosphorylase level, for example by optimization of the medium composition (for example, refer to patent documents 6 and 7), a method of generating objective phosphorylase with high purity using recombinant microorganisms (for example, refer to non-patent document 1 and patent documents 3 to 5), a method of simplifying the purification process (for example, refer to patent document 8), and the like have been known. However, as the process itself can not be changed, these methods have not provided satisfactory results.
Patent document 1: JP-A-1989-91778
Patent document 2: JP-A-1996-280382
Patent document 3: JP-A-1998-14580
Patent document 4: JP-A-1998-276785
Patent document 5: JP-A-1998-327887
Patent document 6: JP-A-1990-154686
Patent document 7: JP-A-1991-4785
Patent document 8: JP-A-2002-345458
Non-patent document 1: Kitao et al., J. Ferment. Bioeng., 73, 179-184(1992)